Shell mold sprue construction



Oct'. 8, 1957 J. J. wEGLARz SHELL MOLD SPRUE CONSTRUCTION Filed Aug- 9.1955 0ct. 8, 1957 J. J. wEGLARz SHELL MOLD sPRuE ooNsTRucTroN 4Sheets-Sheet 2 Filed Aug. 9. 1955 F/GQ ATTORNEY Oct. 8, 1957 J. J.wEGLARz SHELL MOLD SPRUE CONSTRUCTION 4 sheets-sheet s Filed Aug. 9,1955 Oct. 8, 1957 J. J. wEGLARz SHELL -MoLD sPRUE CONSTRUCTION 4Sheets-Sheet 4 Filed Aug. 9. 1955 ...H J-.-- l!" United States Patent' oy SHELL MOLD SPRUE CONSTRUCTION John JQWeglarz, Chicago, lll., assignorto International Harvester Company, a corporation of New JerseyApplication August 9, 1955, Serial No. 527,210

8 Claims. (Cl. 22-134) This invention relates to the casting of moltenmetals or other liquid materials capable of solidication. More inparticular this invention has to do with a sprue construction forconducting clean molten metal into a mold cavity with less turbulenceand reduced amount of metal.

Metal castings made by pouring molten metal into molds withoutprecaution generally .results in a poor grade of product. This generallyis the result ofpermitting dross, oxides, slag and other insolubleimpurities entering the mold cavity and become a part of the casting.Particularly in sand or shell molding a serious problem exists inpreventing such impurities from entering the mold cavity. Turbulence oraspiration during the pouring of the molten metal into the mold tends tosweep in undesirable impurities into the mold cavity. It has been foundthat the quality of the product castings can to a surprisingly largeextent be determined or enhanced by the construction of the sprue orgate means to the cavity of the mold. It is therefore a prime object ofthis invention to provide an improved casting device or sprueconstruction whereby the molten material is conducted uniformly to themold cavity with minimum turbulence or aspiration. a i

A further object of the invention is to provide an improved sprueconstruction whereby substantially all insoluble impurities in themolten material will be trapped in the sprue, thus preventing the entryof said impurities into the mold cavity.

A still further object of the invention is to provide an improved sprueconstruction which, in addition to the preceding objects, requires asmaller quantity or volume of molten material thus reflecting a higherefficiency or yield in castings per lunit weight of said moltenmaterial.

Further objects and advantages of the invention will be apparent fromthe ensuing description, the appended claims and the annexed drawingswherein:

Figure 1 is a perspective view, quarter sectional, showing the assemblyof the two parts comprising the invention, the'upper part being adaptedfor insertion in the cope portion of a mold and the lower part beingadapted.

ingA only the lower part referred to in Figure 1.

Figure 3 is a perspective View, quarter sectional, showing onlythe'upper part referred to in Figure l.

Figure 4 is a side view, in section, of the upper part referred to inFigure 1 taken along the line 4 4 of Figure 3.

Figure 5 is a side view, in section, of the upper part referred to inFigure 1, taken along the line 5 5 of Figure 3.

Figure 6 is a side view, in section, referred to in Figure 1, takenalong Figure 2.

Figure 7 is a side View, in section, of the lower part referred to inFigure 1 taken along the line 7 7 of Figure 2f 1 l Figure 8 is aside`viewtak'en in the direction along of the lower part the line 6 6 ofa 2,808,629 Patented Oct. 8, 1957 the line 8 8 of Figure 1 showing theshape of the solidified material after pouring a mold using the spruecon` struction of this invention.

Figure 9 is an end view taken in the direction along the line 9 9 ofFigure 1 showing the shape of the soliditied material after pouring amold using the sprue construction of this invention.

Figure 10 is a perspective View, quarter sectional, showing the assemblyof the two parts comprising a modilied form of the invention, the upperpart being adapted for insertion in the cope portion of the mold and thelower part being adapted for insertion in the cheek or drag portion ofthe mold.

Figure 11 is a perspective view, quarter sectional, showing only thelower part referred to in Figure 10 Figure 12 is a perspective view,quarter sectional, showing only the upper part referred to in Figure 10.

Figure 13 is a side view, in section, of the upper part referred to inFigure 10 taken along the line 13 13 of Figure 12.

Figure 14 is a side view, in section, of the upper part referred to inFigure l0, taken along the line 14-14 of Figure 12.

Figure 15 is a side view, in section, of the lower part referred to inFigure 10, taken along the line 15-15 of Figure 11.

Figure 16 is a side view, in section, of the lower part referred to inFigure 10, taken along the line 16-16 of Figure 1l.

Figure 17 is a side view taken in the direction along the line 17-17 ofFigure 10 showing the shape of the solidified material after pouring amold using the sprue construction of the invention. p

Figure 18 is an end view taken in the direction along the line 18 18 ofFigure 10 showing the shape of the solidified material after pouring amold using the sprue construction of the invention.

This invention is particularly useful in the metal casting lieldgenerally referred to by the foundry industry as shell molding. Briey,shell molds are generally constructed by packing molding sand, havingabout tive percent by weight of an uncured thermo-setting resinincorporated therein, on a base plate having the cope section of thepattern mounted thereon. The plate and pattern are usually made of heatresistant metal. After the sand and resin mixture is packed against theplate and pattern, heat is applied to the pattern which results inpartly curing the resin binding the sand adjacent the pati tern andplate. The loose sand with uncured'resinis removed leaving a hard crustor shell of the partly cured resin in sand around the pattern and itsassociated plate. The sand shell, plate and pattern are then heated tocure the resin more completely after which the shell is stripped fromthe pattern and plate. The drag section of the shell mold is made in thesame manner after which the two shells are positioned in cooperativerelation and sealed together to form a mold having one or more cavitiestherewithin. The resin used for the binding of the sand may beconveniently of the phenol-formaldehyde condensation type which is wellknown. l

The sprue construction comprising this invention may conveniently bemade as an integral part of the above described shell mold byincorporating as an adjunct to the` cavity pattern the necessaryauxiliary pattern to form the.

sprue construction. Thus the complete shell mold may contain the sprueor gating means for introducing molten metal into the mold cavities aswell as the cavities them-v sprue as used herein is meant to includethat portion` of a mold which conducts liquid metal'into the moldcavities. The mold cavities form the useable cast product while thesprue construction forms the waste metal.

Referring to Figures l to 7.,'the@ numeral 2 0 generally indicates .thesprue vconstruction of this invention in 1as sembled form (Figure l)where-the onepantlorgcope member 21 (Figure 3=) is in cooperativerelation with Jdie second part or drag :element 22 (Figure 2),. In Shellmolding both parts 21 and `22 are constructed entirely of molding sandheld together with a euredthermosetti-ng resin `andmay be madesimultaneously and integrally connected with the cavity`containingportion (not shown) ofthe mold heretofore described. Ofcourse, particularly in the case of liquids capable'of zsolidifyingwithout involving very high temperatures, the sprue construction-'ofthis invention may be made of other material.

From Figures l and 3l it will .be noted that the wall ,26 of the copemember 21 forms a horn-shaped .opening 23. This opening 23 is a pouringbasin adapted for receiving the liquid material or molten-metal pouredfrom a suitable ladle (not shown). The upper portion of theopening 23 isgenerally referred to in the industry ,as 'the basin while the lowerportion is generally referred to as the downsprue. However, for purposesherein, it will be most convenient to combine these two terms byreferring to the entire opening from the upper lip 24 to the lower`oriiice 25 as the basin or pouring basin.

As stated previously the contour of .thebasin 23 as formed by the wall26 is preferably horn-shaped. The basic reason for a horn-shaped contourof the basin Y23 is that it has the effect of reducing the turbulence ofthe liquid poured into the basin from a ladle because .the wall 26 iswithout creases or other obstruction yand the liquid is caused to flowdownwardly and smoothly along the wall 26.

The bottom 29 of the basin -23 is dome-shaped and is formed by a wall 39of the drag element 22 as best shown in Figures 1 and 2.

The drag element 22 at the bottom portion 3d adjacent to the bottom 29of the basin 23 is curved, downwardly to form a well 27 with a pair ofvertically extending in spaced relation parallel disposed walls 2S, `oneof which walls is shown in Figures l and 2. Thus the well 27 formed bythe wall 31 and the lower portion of the parallel spaced walls 28 may beconveniently considered to eX- tend vertically to the orifice 25. Itshould be understood that the sprue construction of this invention maybe cornprised of a plurality of such wells 27 disposed about theperiphery of the bottom 29 of the basin 23 in like manner as illustratedin Figure l. For convenience two such wells 27 are illustrated in Figure6.

Now directly above and contiguous to each well 27 there is disposed anopening or trap chamber 32. The trap chamber 32 is formed by theinternal surface of walls 26 and 26 of the cope member 21 with the pairof vertically extending walls 2S of the drag element 22. The trapchamber 32 and its associated well 27 is cornmunicatively connected forfluid flow with the basin 23 adjacent the bottom of the basin by meansof an outlet passage 33. Thus molten metal entering the basin 23proceeds downwardly to the bottom 29 and thence outwardly through thepassage 33 into the well 27 and rises to the upper portion of the trapchamber 32. It should be understood that where the sprue construction ofthis invention is provided with a plurality of wells 27 and associatedtrap chambers 32, the passage 33 may conveniently be extendedcircumferentially to provide outlet means for the molten metal from thebasin 23 to each of the wells 27 and associated trap chambers 32.

.Leading from the upper portion of each well 27 there is provided one ormore channels or runners 34. One end of each runner 34 extends to atleast one cavity of the mold (not shown) and the other end merges withthe upper portion of a well 27 thereby connecting communicatively forfluid tlow one or more mold cavities with the well 27 and provides meansfor conducting molten metal from the well to the cavities. The runners34 are formed merely by interposing a channel formation 37 in the basewall 35 of the cope member 21 which cooperates with the base Wall 36 ofthe drag element 22 to form the runners 34 one of which is shown inFigure l.

The speed or velocity of movement of molten material should be retardedduring the period `it passes from the outlet passage 33'through the well27 to the runners 34.

By retarding the motion of the molten material in the'k well it allowssuicient time for insoluble impurities of less density to float upwardsinto the trap chamber 32 where they are trapped in the upper portionthereof as shown at 38' in Figures 8 and 9. This may be accomplished bymaking the outlet passage 33 leading to each well 27 of across-sectional opening substantially equal to the combinedcross-sectional areas of the runners leading to a given well 27. Thusthe hydraulic head created in the basin causes the flow of moltenmaterial emanating from the passage 33 to divide, part to the lowerportion of the well 27 and associated trap chamber 32 and the balancebeing directed through the runners 34. Further, the minimizing ofturbulence of molten metal poured into the horn-shaped .basin 23materially reduces the amount of air bubbles conducted through thepassage 33. From this it may readily be understood by those skilled inthe art that the liquid entering the runners 34 to the cavities will besubstantiallyfree of insoluble impurities. Of course insolubleimpurities of greater density than the liquid would settle to the bottomof the well 27 as shown at 39 of Figures 8 and 9.

Referring now to Figures 8 and 9 of the drawings there is illustratedthe 4shape of the waste metal formed by the sprue construction of thisinvention after solidification of the molten metal and the sand shellremoved therefrom. The trap chamber 32 forms the portion of metaldesignated 32 while the Vwell 27 forms the` portion of metal designated27. The basin 23 forms the metal portion 23 and the passage 33 forms themetal portion 33'. Similarly the runners 34 leading to the mold cavities(not shown) forms the portion of metal 34.

The upper portions of the projections 32 indicated at 38' show thecollection of insoluble materials of lower density trapped by the trapchamber 32 while the insoluble materials of high density are collectedat the bottom of the well 27 and retained in the waste metal portiondesignated at 39. Y

It will be noted the thickness of the projection 32 is relatively lsmallas compared to ,that of 23. Thus but a relatively small amount of metalor other casting material is required to effectively trap insolubleimpurities resulting in a much improved quality ofproduct castings.

Figures 10 to 18 illustrate a modified form of the invention. Brieiy thecope member is modified to terminate the wall 26 (Figure 3) at the lip24 thereby .elimi-` nating the wall 26 from the lip 24 to the orifice2S. The drag element (Figure 2) is modied to bring the walls 26 in acloser spaced relation. Thus the assembly of the cope member with thedrag element results in that the outlet passage 33 of Figure 1 extendsto the lip 24 at the top of the basin 23.

Having the above in mind we new describe the particular construction ofthe sprue comprising a modified form of this invention.

Referring to Figures 10 to 18 the numeral 120 gener ally indicates themodied construction of this invention in assembled form where the onepart or cope member 121 is in cooperative relation with the second partor drag element 122 (Figure 11). Similarly as described in the precedingembodiment both parts are constructed of molding sand held together witha cured thermo-setting resm.

From Figures 10 and l1 it will be noted `that the wall 126 of the dragelement 122 forms a horn-shapedopenng 123. The opening 123 is a pouringbasin adapted for receiving the liquid material or molten metal pouredfrom a suitable ladle (not shown), The basin 123 extends downwardly fromthe lip 124 to the bottom wall 130. The bottom 120 of the basin 123formed by the wall 130 is dome-shaped as will be noted from Figure` 11.

As Will be noted from Figures 10, 11 and 15 the bottom portion 130 ofthe drag element is curved downwardly to form a Well 127 with a pair ofvertically eX- tending in spaced relation parallel disposed walls 128,one of which walls is shown in Figures 10 and 1l and 15. Thus the well127 formed by the wall 131 and the lower portion of the parallel spacedwalls 128 may be conveniently considered toextend vertically tothehorizontal plane formed by the, base or wall 136 of the drag element122. As before it should again be understood that modited form of sprueconstruction of this invention may be comprised of a plurality of suchwells 127 disposed about the periphery of the bottom 129 of thejbasin123 in like manner as illustrated in Figure' 10. For convenience twosuch wells 127 are illustrated in FigurelS.

Similar to the first embodiment previously described, directly aboveeach ,well 127 there is disposed an opening r trap 132. However, thetrap, 132 is not a chamber as the opening is contiguous to the basin 123from the lip 124 down to the bottom of the basin 123. The trap 132 istherefore an opening formed by the parallel walls 128, the Well 127 ofthe drag element 122 and the wall 126 (Figures and 12) of the copemember 121. From this it can be seen that the trap 132 Vand itsassociated well 127 is cormnunicativelyV connected for fluid ow with thebasin 123 by means of an outlet passage 133, which passage extends fromthe lip 124 downward to the bottom 129. Thus molten metal entering thebasin 123 passes into the trap 132 and associated well 127 through thepassage 133. It can berfurther seen that where the modied sprueconstruction of this invention is provided with a plurality of wells 127and associated traps 132, a separate passage 133 connects eachrespective trap and Well with the basin 123.

As in the previously described embodiment, leading from theupperportio'n of each Well 127 there is provided one or more channels.orrunners'134. One end of each runner 134 extends to at least onecavity of the mold (not shown) and the other end merges with the upperportion of a well 127 thereby connecting communicating for uid ow one ormore mold cavities with the well 127 and providing means for conductingmolten metal from the well to the cavities. The runners 134 are formedmerely by interposing a channel formation 137 in the base wall 135 ofthe cope member 121 which cooperates with the base wall 136 of the dragelement 122 to form the runners 134, one of which runners is shown inFigure l0.

. Nowit can be appreciated that ow of molten metal from the basin 123into the trap 132 to the runners 134 will be governed by thecross-sectional area of the elongated passage 133. Since thecross-sectional area of the passage 133 is in turn governed by thespaced relation between the walls 128 it follows that the spacingbetween the parallel disposed walls must be adjusted to attain across-sectional area of the passage 133 substantially equal to thecombined cross-sectional area of the runners 134 leading to the Well127.

By referring to Figures 17 and 18 illustrating the shape of the wastemetal formed by the modified sprue construction of this invention aftersolidiication of the molten metal and sand removed therefrom andcomparing sarne with Figures 8 and 9 of the previously describedembodiment, it will be seen that the trap portion 132 of Figures 17 and18 is much thinner than the corresponding trap portion 32 of Figures 8and 9. Thus less waste metal together with less quantity of sand andresin mixture are the advantageous results of the modified form of theinvention as compared with the rst described embodiment. It will also benoted that the waste metal portion 132 is integrally connectedthroughout the vertical length of 6 the waste metal basinvportion 123fwhereas in the previously described embodiment the` portion 32 isconnected to the basin only at the lower end. n

In the modified sprue construction when the molten metal is poured intothe basin 123, forming the waste metal portion123 (Figures 17 and 18),it tiows through the elongated passage 133 into the trap 132 and well127 forming the portions 132 and 127' respectively. Since the velocityof the molten material is retarded in the well and trap insolubleimpurities of lesser density oat to the top as indicated at 138 Whilethe, higher density insoluble impurities settle at the bottom lof thewell as indicated at 139 thus permitting a much purer form of moltenmetal to enter the mold cavities through the runners 134 formingthewaste metal 134 of Figures 17 and 18.

Having described this invention in its preferred embodiments it shouldbe Vunderstood that further modication may be made therein .withoutdeparting from the spirit of the inventionorrthe scope of the appendedclaims.

What is claimed is: v Y

1. In combinationwith aV mold having at least one cavity adapted forcasting of a liquid capable of solidiiication, an improved sprueconstruction comprising a cope member and a drag element in cooperativerelation forming avertically extending pouring basin having at least oneoutlet passage adjacentthe bottom thereof, a well disposed adjacent toand extending'below said basin, a vertically extending liquid trapdisposed above said well, at least one runner disposed in substantiallythe same plane as said passage andcommunicatively connecting for tluidflow each cavity with said well and trap, said passage being adapted toconnect communicatively for fluid flow said basin With said well, saidpassage having a cross-sectional area substantially equal to thecombined cross-sectional area of said runners to each cavity of saidmold for hydraulically minimizing the flow velocity and turbulence ofliquidin said well thereby facilitating the flotation of insolubleimpurities of said liquid into said trap. Y v

2. In combination with a mold having at least one cavity adapted Iforcasting of aV liquid capable of solidification, an improved sprueconstruction comprising a pouring basin having at least oneAoutletpassage adjacent the bottom thereof, a well disposed adjacent toand extending below said basin, a vertically extending liquid trapdisposed above said well, at least one runner disposed in substantiallythe sameplane as said passage and communicatively connecting for fluidow each cavity with said Wall and trap, said passage being adapted toconnect communicatively for uid ow said basin with said Well, saidpassage having ,a cross-sectional area substantially equal to thecombined cross-sectional area of said runners to each cavity of saidmold for hydraulically minimizing the ow velocity and turbulence ofliquid in said Well thereby facilitating the ilotation of insolubleimpurities of said liquid into said trap.

3. In combination with a mold having at least one cavity adapted forcasting of a liquid capable of solidification, an improved sprueconstruction comprising a cope member and a drag element in cooperativerelation forming a vertically extending pouring basin having at leastone outlet passage adjacent the bottom thereof, a well disposed adjacentto and extending below said basin, a vertically extending liquid trapchamber disposed above said well, at least one runner disposed insubstantially the same plane as said passage and communicativelyconnecting for fluid ow each cavity with said well and trap chamber,said passage being adapted to connect communicatively for iiuid ow saidbasin with said well, said passage having a cross-sectional areasubstantially equal to the combined cross-sectional area of said runnerto each cavity of said mold for hydraulically minimizing the flowvelocity and vturbulence of liquid in said well thereby facilitating theilotation of insoluble impurities of said liquid into said trap chamber.

4. In combination with a mold having at least one cavity adapted forcasting of a liquid capable of solidiiication, an improved sprueconstruction comprising a pouring basin having at least one outletpassage adjacent the bottom thereof, a well disposed adjacent to andextending below said basin, a vertically extending liquid trap chamberdisposed above said Well, at least one runner disposed in substantiallythe same plane as said passage and communicatively connecting for fluidflow each cavity with said well and trap chamber, said passage beingadapted to connect communicatively for fluid ovv said basin with saidwell, said passage having a cross-sectional area substantially equal tothe combined cross-sectional area of said runners to each cavity of saidmold for hydraulically minimizing the ow velocity and turbulence ofliquid in said Well thereby facilitating the flotation `of insolubleimpurities of said liquid into said trap chamber.

5. In combination with a mold having at least one cavity adapted forcasting of a liquid capable of solidiication, an improved sprueconstruction comprising a pouring basin having at least one outletpassage adjacent the bottom thereof, a well disposed adjacent to saidbasin, a vertically extending liquid trap chamber disposed above saidwell, at least one runner disposed in substantially the same plane assaid passage and communicatively connecting for iiuid flow each cavitywith said well and trap chamber, said passage being adapted to connectcommunicatively for uid ow said basin with said well, said passagehaving a cross-sectional area substantially equal to the combinedcross-sectional area of said runnersto each cavity of said mold forhydraulically minimizing the flow velocity andV turbulence kof liquid insaid well thereby facilitating the flotation of insoluble impurities ofsaid liquid into said trap chamber.

6. In combination with a rnold having at least one cavity adapted forcasting of a liquid capable of solidication, an improved sprueconstruction lcomprising a cope member and a drag element in cooperativerelation forming a vertically extending pouring basin having at leastone outlet passage, a Well disposed ,adjacent to and extending belowsaid basin, a vertically extending liquid trap disposed abover saidWell, 4said trap being contiguously connected to and substantially oo-extensive with said basin and said passage, atleast one runnerdisposed in substantiallythe s ame plane as said passage and comwell,said passage having a cross-sectionallarea substantially equal-to nthecombined cross-sectional area of said runners to 'each ,cavity of saidkmold for hydraulically minimizing the :flow velocity and turbulence ofliquid in said well therebyfacilitating the 4flotation of insolubleimpurities of 'said liquidinto said trap. Y 7. In, combination with amold having at .least one cavity -adaptedfor casting of a liquid capableof soliditication, an improved sprueV construction comprising a pouringbasin having at least one outlet passage, a well disposed adjacent toand extending below said basin, a vertically extending liquid ytrapdisposed above said well, said trap being contiguously connected to andsubstantially co-extensive with said basin and said passage, at leastone runnerdisposed in substantially the same plane as said passage andcommunicatively connecting for fluid flow each cavity with said well.and trap, said passage being adapted to connect communicatively for`fluid flow said basin with said well, said passage having acrosssectional area substantially equal to the .combined crosssectionalarea ofsaid runners to each cavity of said mold for hydraulicallyminimizing the flow velocity and turbulence of liquid in said wellthereby facilitating the Yiiotation of insoluble impurities of saidliquid into said trap.

8. In combination `with a Vmold having at lleast one n cavity adaptedfor casting of a liquid capable of soliditication, an improved sprueconstruction comprising a pouring basin having at least one outletpassage, a well disposed adjacent to said basin, a vertically extendingliquid trap disposed above said well, said trap being contiguouslyv4connected to and substantially co-extensive with said basin and saidpassage, at least one runner disposed in substantially the same plane assaid passage and communicativeljy connecting for fluid ow each cavitywith said well and trap, said passage being adapted to connectcommu-nicatively for fluid flow saidbasin with said well, said passagehaving a cross-sectional area substantially equal to the combinedcross-sectional area of said runners to each cavity of said mold forhydraulically minimizing the ow velocity and turbulence vof liquid insaid well thereby facilitating the notation of insoluble impurities ofsaid liquid into said trap.

References Cited in the le of this patent UNITED STATES PATENTS1,030,066 Erlandson .Tune 18, 1912 1,100,831 Kline lune 23, 19141,410,775 Thomes Mar. 28, 1922 V1,992,677 Sorensen Feb. 26, 19352,691,196 Banister Oct. 12, 1954 FOREIGN PATENTS 620,670 vGreat BritainMar. 29, 1949

